In the analytical and diagnostic fields there is a need to uniformly mix liquid laboratory reagents and a patient sample during and prior to chemical analysis and it is known that ultrasonic energy may be used to successfully provide such mixing. The source of ultrasonic energy is typically an ultrasonic horn, a relatively elongated member which vibrates at an ultrasonic frequency as a result of a conversion of an electrical excitation signal into a mechanical vibration. In use, ultrasonic energy is coupled into a reaction compartment containing the liquid laboratory reagent(s) and patient sample in a solution to be mixed resulting in the creation of relatively high sonic energy zones within the composition. Unfortunately, experience has shown that ultrasonic mixing of such a composition may be inadequate for various reasons including too little energy, too short a mixing time, or an improperly shaped mixing vessel. In these instances, inadequate mixing may result in zones of non-uniformity within the liquid solution (sample and reagents) to be analyzed and impart an unwanted degree of inaccuracy during chemical analysis. One approach to this problem is to provide ultrasonic mixing for a period of time in excess of a minimum time predetermined to achieve the desired degree of uniformity, however, such an approach has an adverse impact on throughput. Accordingly, it would be advantageous to provide a method to determine whether the mixing energy applied to a solution within a vessel has produced the desired uniformity of mixing of the sample with liquid reagents. If not, non-homogenous solution zones may remain therein, in which event, an operator may be alerted to prevent an otherwise undetectable adverse impact upon the accuracy of a reported sample analysis.